FIG. 2 shows a construction of an address buffer circuit as a prior art superconducting integrated circuit device. In FIG. 2, the reference numerals 7, 8, 9, and 10 designate Josephson junction elements, the numerals 13, 14, 15, and 16 designate connection nodes, and the numerals 3, 4, 5, and 6 designate superconducting strip lines connected between the connection nodes.
The operation of the device will be described with reference to operation waveforms of FIG. 3.
The inductance of the strip line 3 is significantly lower than the inductance of the strip line 4, and similarly the inductance of the strip line 5 is significantly lower than that of the strip line 6. When a DC bias current I.sub.B is applied in this state, almost all of the current I.sub.B flows through lines 3 and 5 including to ground through Josephson junction elements 7 and 9 of the ratio of inductances of lines 3 to 4 and lines 5 to 6, respectively. An off-set signal I.sub.off is applied in a reverse direction from that of an address signal I.sub.C. These signals affect the state of the Josephson junction elements because of their proximity. The signals flow through superconducting strip lines as indicated in FIG. 2. The explanation of the switching behavior of the device of FIG. 2 is based on the application of the signals shown in FIG. 3 while a constant biasing signal I.sub.B is applied. The offset current I.sub.off is also constant in direction and amplitude. The address signal I.sub.C is pulsed.
When an address signal I.sub.C is applied, the Josephson junction element 7 is switched so that most of the biasing current flows through strip line 4 to output a "1" signal to output A. On the other hand, the Josephson junction element 9 is not switched because the off-set signal I.sub.off and the address signal I.sub.C cancel each other. Accordingly, A="0" is output. When the address signal I.sub.C is inverted in this state, the Josephson junction elements 8 and 9 are switched, and A="0", A="1" are output. This prior art device uses non-latching states of the switching gates, and in this way the address signal I.sub.C is directed to A and A.
The prior art superconducting integrated circuit device is a current control, and it was difficult to introduce the it into a light information processing system and light communication system.